IPSWICH, England – Detectives hunting a serial killer were expected to identify the two latest victims on Wednesday, as police warned prostitutes to stay off the streets for their own safety.

Five bodies have turned up in the past 11 days, and the latest discoveries — the bodies of two women, found at the side of a busy road — are believed to be prostitutes who were recently reported missing.

Police have not officially confirmed that the bodies are those of Paula Clennell, 24, and Annette Nicholls, 29, but Detective Chief Superintendent Stewart Gull said it was a "natural assumption."

Clennell's father Brian said he didn't know his daughter had worked as prostitute, and he was "going through hell."

"I never knew that she lived the life that she did," Clennell told the BBC. "Somebody out there must know, somebody that's doing this. He's sick, he's got to be caught. It could be somebody's father, it could be somebody's uncle, it could be anybody."

Suffolk police were already investigating the deaths of three other women — all of whom had worked Ipswich's red-light district — whose naked bodies were found a few miles apart. One was found in a stream, another in a pond and a third in the woods, about 30 yards from a road.

The two bodies discovered Tuesday were lying near a busy road near Levington, Suffolk, a village about five miles south of Ipswich.

All five corpses were found within a few miles of Ipswich, a small city about 70 miles northeast of London.

Ipswich only has about 40 prostitutes working the street, said Hannah Besley, a community safety officer in Ipswich who chairs of the city's Prostitution Steering Group. When the first women vanished, most of the prostitutes — including Clennell, who disappeared after the first two bodies were discovered — kept working, but that's no longer the case.

"It's now gotten to such a critical stage that they are terrified, and last night it was very quiet — reassuringly so," Besley said.

Forensic officers remained at the scene where the latest bodies were found, and a wide cordon was set up to secure the area.

So far, police have only been able to determine the cause of death in one of the five cases. Anneli Alderton, a 24-year-old whose body was discovered in a wooded area on Sunday, had been asphyxiated, and likely strangled, Gull said.

Police are uncertain how 25-year-old Gemma Adams and 19-year-old Tania Nicol were killed. Their bodies were both found in water; Gull said that has hampered the forensic investigation.